Structural, electrical conductivity and dielectric relaxation behavior of LiHf2(PO4)3 ceramic powders

Abstract

Lithium hafnium phosphate LiHf2(PO4)3 (LHP) was synthesized via solid-state synthesis technique. The sintering behavior, structure, and phase composition of the as-prepared sample was analyzed using X-ray diffraction (XRD) characterization technique. The XRD-Rietveld refinement analysis showed that after sintering at low temperatures 500 to 1000 °C, it exhibited various secondary phases. However, a single phase was observed as the sintering temperature increases from 1100 to 1200 °C. LHP sintered at 1100 °C produced real features of sodium superionic conductor type (NASICON-type) with hexagonal crystal axis indicating R-3c space group. The electrical properties were studied using impedance spectroscopy technique. Frequency and temperature dependence behavior of conductivity (ac and dc) and dielectric permittivity were studied. The results obtained describes the conduction mechanism in the system. Electric modulus formalism was performed to investigate the relaxation behavior which showed that as measuring temperature increases, the relaxation frequency increases whereas relaxation time decreases. This behavior explains the hopping mechanism of the charge carriers in the system. Likewise, the correlated barrier hopping model elucidates the dominant hopping mechanism.

Optical and functional properties of hydrothermally synthesized tetragonal Ba0.4Cu0.6−xLaxTiO3 (x = 0.2–0.6) nanoparticles

“…From this data, it was understood that there was a proportional relationship between average crystallite size and microstrain. This type of observation was also found in the literature [20][21][22][23][24][25][26]. The lattice constants were evaluated and presented in table 1.…”

Analysis of thermal and electrical conductivity properties of Al substitution LiHf2(PO4)3 chemical solid electrolyte

“…2. The XRD results of unsubstituted LHP shows the sample powder sintered at 1100 °C for 3 h exhibited single phase with no secondary phases as reported elsewhere [16]. The unit cell volume and lattice parameters of the LHP analyzed are shown in Table 2 and the parameters are found to be in close agreement with the data reported by Chang et al [17,18] where a = b = 8.8285 Å, c = 22.0190 Å and V = 1484.40 Å 3 .…”

“…The presence of space charge also contributes to the increase in the conductivity. It is also observed that the un-substituted LHP pellet showed low AC conductivity in the order of 2.45 × 10 −4 Ω −1 m −1 at room temperature as reported elsewhere [16]. On the other hand, the Al substituted sintered pellets exhibited high Li ionic conductivity than the un-substituted LHP.…”

Influence of Bi on dielectric properties of GaAs1−xBix alloys

“…4 as a shoulder on the right-hand side of the horizontal axis, has been calculated as 2.5 µs. When the arrangement of relaxation times is considered, the relaxation times of the order of ms and µs can be attributed to dipolar [23] and ionic polarizations [24], respectively. The sizes of semicircles become smaller with increasing Bi content.…”